s=input()
num = int(s)
res = "No"
if num>=30:
 res= "Yes"
print(res) s=input() s input() input num = int(s) num int(s) int s res = "No" res "No" if num>=30:
 res= "Yes" num>=30 num 30 res= "Yes" res "Yes" print(res) print res s=input() input() s res = "No" "No" res res= "Yes" "Yes" res num = int(s) int(s) num
s=input()
num = int(s)
res = "No"
if num>=30:
 res= "Yes"
print(res)